In recent years, in the field of ink jet printer as an image forming apparatus, a complex copying machine, which serves not only as a printer but also as a copying machine and a facsimile communication equipment, has been developed by adding an image reading unit (scanner section) and a modem.
However, such complex copying machine presents a problem that vibrations occur when scanning by the ink carriage in a printer section, which in turn causes blur in the reading operation by the scanner section. As to the conventional copying machine of the electrophotographic printing system wherein an image reading operation and an image forming operation are performed, since a photoreceptor drum or various types of rollers rotate at fixed speed, the adverse effects of the foregoing vibrations are less likely to occur.
In response, Japanese Unexamined Patent Publication No. 2001-334648 (published on Dec. 4, 2001) and Japanese Unexamined Patent Publication No. 5-48849/1993 (published on Feb. 26, 1993) disclose typical solution to the foregoing problem. Namely, these publications disclose the technique of suppressing blur by arranging so as to start the scanning operation of the printer section after temporality stopping the scanning operation.
However, when adopting the foregoing conventional techniques, the printer section does not perform an operation during the scanning operation by the scanner section, thereby presenting another problem in that relatively a long time is needed for an overall image forming operation.